After going 4 1/2 years without collecting a major championship, now firmly in his mid-30s, he heads into Monday’s start of the U.S. Open with a chance to win his third such trophy of 2017.

“I mean, I have a hard time thinking I could win three Slams in one year. It just sounds totally surreal to me,” Federer said in an interview with The Associated Press. “But I’ll prepare myself the best way possible, so that I will have the best chance to really excel there in New York.”

Yes, Federer is most certainly back. All the way back. He’s back in the field at Flushing Meadows after sitting out the hard-court tournament a year ago while taking off the last half of the season to let his surgically repaired left knee heal. And he’s back in the role of Grand Slam title favourite after winning the past two majors he entered, the Australian Open in January and Wimbledon in July.

Is he playing as well as — or perhaps better than — ever?

“I don’t know. It’s hard to tell. It doesn’t really matter to me. I would hope that I’m a better player today, just (by) virtue of time that’s gone by and I’ve had time to practice and train and all that stuff,” he said with a sigh. “But better? In a way, I would hope so.”

Federer turned 36 on Aug. 8, making him older than all but two men to have ever won the most important tennis tournament held in the United States, an event first held in 1881.

He will be facing a depleted draw in New York as he seeks his first title there in nearly a decade.

Three-time major champion Andy Murray, recently replaced at No. 1 by Rafael Nadal, has been dealing with a sore hip and hasn’t played since Wimbledon. Neither has 2014 U.S. Open champion Marin Cilic, sidelined by a foot blister.

Reigning U.S. Open champion Stan Wawrinka, who had knee surgery, and 2016 runner-up Novak Djokovic, whose right elbow is injured, are out for the rest of the season. So is 2014 runner-up Kei Nishikori, because of a hurt wrist, the same injury that will keep Canada’s Milos Raonic out of action next week.

Wawrinka, Djokovic and Nishikori are following Federer’s example. Skipping the Rio de Janeiro Olympics, the U.S. Open and other tournaments allowed him to return to the ATP Tour refreshed and reinvigorated, not to mention fully fit.

The payoff? He is 35-3 with five titles this season.

“The long break last year really helped him. He (went) a little bit away and looked at everything from the outside again. It gives you a little bit of distance,” said Severin Luthi, one of Federer’s coaches. “In general, I know with him that if he takes a break and if he’s fresh, happy to play, motivated … that’s one of his biggest strengths.”

The day before beating Cilic in the final at the All England Club to claim his eighth Wimbledon championship and 19th at a major overall — both records for a man — Federer sat down with Luthi to discuss preparation for the U.S. Open.

Yes, time marches on, even for Federer, although it doesn’t really seem as if that’s the case at the moment.

“He’s been playing amazing tennis,” said 20-year-old Alexander Zverev, considered the sport’s next potential great.

“He pretty much won every single big tournament he played this year,” added Zverev, who defeated Federer in the hard-court final at Montreal this month. That was the last time Federer was in action; he tweaked his back and withdrew from a tuneup in Ohio the following week.

If his back is problematic at Flushing Meadows, it could stand in Federer’s way. Otherwise, he could be the last man standing there for the first time since winning his last of five consecutive U.S. Open titles in 2008.

That would please Federer, of course. But what he really derives satisfaction from lately is his aggressive style on court.

“I like the way I’m playing. I’m playing going forward. I’m going for it. I’m not holding back. I’m playing the kind of tennis I like to play, personally, myself. And I’m not, like, doing everything only for success. I’m actually letting it fly off my racket. And that makes me happy,” he said.

“People who’ve been waiting for me to come back strong, maybe one more time, I’ve given them even more now by winning a couple of Slams this year. So it’s extremely special times. I’m aware of that. I know it’s just only bonus, whatever is about to come,” Federer continued, with a hint of a smile. “So I hope I can keep this level up and then maybe good things can continue. We’ll see.”